This application claims priority to Japanese Patent Application No. 2000-038240, filed Feb. 10, 2000.
1. Technical Field
The present invention relates to a recording and reproducing apparatus and a recording and reproducing method using helical-scan technology for recording and/or reproducing data on magnetic storage media.
2. Prior Art
In the field of magnetic recording, there is an increasing demand for recording and reproducing a large amount of high-quality voice and video signals. An amount of information to be handled increases drastically. Further, a high transfer rate is required. A so-called helical-scan system is proposed and is put to practical use as a recording and reproducing system for providing a large-size storage capacity and a high-speed transfer rate.
The helical-scan system is used for, say, a video tape recorder (VTR), a digital audio tape (DAT), and the like. The helical-scan system comprises a magnetic head on a fast rotating drum. By moving the tape around this drum, the helical-scan system fast records or reproduces data diagonally across the magnetic tape.
In recent years, however, there is an increasing demand for an improved recording density due to a further increasing amount of information to be processed and from the viewpoint of needs for a small-size and large-capacity recording and reproducing apparatus. Narrowing a track pitch is one technique for improving the recording density.
With a conventional helical-scan system, however, narrowing a track pitch makes it difficult to stably and accurately perform recording and reproduction.
Track pitches rather greatly fluctuate due to minute errors at respective parts for each recording and reproducing apparatus. These errors are specifically caused by irregularities in magnetic head shapes during manufacturing, installation positions of magnetic heads on the rotary drum, rotational speeds of the rotary drum, and tape tensions applied to the magnetic tape.
There may be the case where the track pitch is designed to be a very small value such as several microns for a recording and reproducing apparatus using the helical-scan system. In this case, the above-mentioned minute errors at respective parts cause a track pitch error which is not negligible. This makes a normal recording and reproducing operation difficult.
Further, in recent years, there is an increasing demand for a much higher transfer rate in order to fast process a large amount of information.
However, for example, the conventional helical-scan system implements a high transfer rate by increasing the number of magnetic heads on a rotary head. Irregularities in magnetic head shapes or installation positions greatly affect the track pitch accuracy for each magnetic head, causing a problem of increasing track pitch unevenness.
To solve the above-mentioned problems, it is therefore an object of the present invention to provide a recording and reproducing apparatus and a recording and reproducing method for achieving a high recording density and a high transfer rate, and stably and accurately performing recording and reproduction.
A recording and reproducing apparatus comprises a rotary drum provided with at least one recording and reproducing head having m head elements (where m is 2 or larger integer) for recording and/or reproducing a magnetic signal on a magnetic recording medium; and a feed mechanism for wrapping a magnetic recording medium halfway around the rotary drum and feeding this magnetic recording medium at a specified feed speed. The following relationships expressed in equations 1 and 2 are satisfied among a track width W for each of the head elements, a track pitch Tp between the head elements, and a feed amount S for a magnetic tape medium fed by the tape feed mechanism until the recording and reproducing head scans the magnetic recording medium next.
mW/2 less than Tp less than 2mWxe2x80x83xe2x80x83Equation 1 
nTpxe2x88x92W less than S less than nTp+W (where n is an integer)xe2x80x83xe2x80x83Equation 2 
The thus configured recording and reproducing apparatus can perform recording and reproduction on a plurality of recording tracks at a time using a plurality of head elements while the recording and reproducing head scans a magnetic recording medium.
A recording and reproducing method according to the present invention performs helical-scan recording and/or reproduction for a magnetic recording medium by using a recording and reproducing apparatus comprising a rotary drum provided with at least one recording and reproducing head. The following relationship in equation 3 is satisfied when the recording and reproducing head uses a magnetic head comprising m head elements (where m is 2 or larger integer) with each track width W and a track pitch Tp between the head elements. The following relationship in equation 4 is satisfied with respect to a feed amount S for a magnetic recording medium to be fed until the recording and reproducing head scans the magnetic recording medium next.
mW/2 less than Tp less than 2mWxe2x80x83xe2x80x83Equation 3 
nTpxe2x88x92W less than S less than nTp+W (where n is an integer)xe2x80x83xe2x80x83Equation 4 
The above-mentioned recording and reproducing method can perform recording and reproduction on a plurality of recording tracks at a time using a plurality of head elements while the recording and reproducing head scans a magnetic recording medium.
As mentioned above, the recording and reproducing apparatus and the recording and reproducing method according to the present invention can perform recording and reproduction on a plurality of recording tracks at a time using a plurality of head elements while the recording and reproducing head scans a magnetic recording medium. Namely, a plurality of head elements mounted on the recording and reproducing head are used for concurrent recording and reproduction on a plurality of recording tracks. This configuration prevents track pitch errors from increasing due to accumulated installation errors for each head element. If a track pitch is narrowed for increasing the recording density, it is possible to stably and accurately perform recording and reproduction. Further, recording and reproduction is performed on a plurality of recording tracks at a time, making it possible to increasing a transfer rate.